This invention relates to switch devices having liquid level control capability and more particularly to those which are used to control the level of carbonated liquid contained in a vessel or storage tank associated with ordinary liquid vending machines.
Previously, vending machines of the aforementioned type have been required to contain vessels for storage of the carbonated liquid in a manner which when empty would necessitate the replacement of the vessel. It became particularly desirable to have a vessel or storage tank of a replenishable nature thereby obviating the necessity of replacing the vessels when empty. Concurrent with this desired development, it was necessary to have a sensing device adapted to determine the liquid level of the carbonated fluid or the like located within the replenishable tank. Probe devices were developed in which an annular magnet located upon a float element traversed vertically along a probe thereby activating or deactivating a reed switch of the conventional type.
Similarly, it became desirable to have a float control device able to maintain an extended fluid inlet cycle due to the dilaterious effect upon pump motors caused by rapid on-off operation, occasioned by small changes in the liquid level of the tank and associated traversal of the annular magnet. This has previously been accomplished, as in the U.S. Pat. No. 3,408,053, by an internally disposed magnetic sleeve element which caused the latch type components of the reed switch to maintain a juxtaposed relationship longer than would occur under normal activation by the position of an annular ceramic magnet located on the float element.